Acta Medica Croatica最新文献

Patients with the end-stage renal disease who demand replacement of renal function are faced with numerous concomitant diseases and conditions, as well as with the possible side-effects and complications of the dialysis procedure. Intradialytic complications include hypotension and cardiac arrhythmias caused by rapid changes in electrolyte concentration and volume status. Long-term complications include increased incidence of cardiovascular diseases, malnutrition and increased mortality. Two major mechanisms are involved in removal of uremic toxins through the dialysis membrane: diffusion and convection. Diffusion removes only low molecular weight substances, while larger molecules may be removed by convection which also enables larger ultrafiltration. Haemodiafiltration (HDF) combines diffusion and convection. Convective transport may be enhanced by increased volume of suspstitution fluid. In order to avoid impractical addition of solutes in the bags, online (OL)-HDF has been constructed. Substitution fluid is prepared directly in the dialysis machine, in non-limited quantity with high level of microbacterial purity. It is obligatory to employ high-flux dialysers, while it is necessary to achieve high ultrafiltration with transmembrane pressure < 300 mmHg, what demands appropriate hydraulic sieving potential and surface. Sieving coefficient must be high enough to enable passage of bigger toxins, but to prevent loss of albumin. Patients treated with OL-HDF have decreased incidence of hypotension, cramps and cardiac arrhythmias. Dialysis dose is 30% higher with significant decrease in the concentration of beta2-mycroglobulin. Additional effects are favourable profile of leptin, one of the regulators of nutritional status in dialysis patients, as well as the antiinflammatory effects.

Acute and especially chronic renal failure (CRF) are relatively common and important risk factor for morbidity and mortality in patients after heart, lung, liver or intestine transplantation. Numerous factors contribute to the development of CRF in this group of patients, like treatment with calcineurin inhibitors and other nephrotoxic drugs in the perioperative period, hemodynamical changes during and after the surgery, preexistent renal disease, hypertension, diabetes mellitus, dyslipidemia and anemia. Pretransplant evaluation of renal function is mandatory to predict which patients have increased risk for development of CRF. In the posttransplantation course it is necessary to timely diagnose and treat renal failure, while patients with insufficient renal function have 4.55-fold increased risk of death compared to patients with normal renal function. Special problem is diagnostic approach to patients with suspected chronic renal disease who are candidates for transplantation of other parenhimatose organs. Diagnostic value of serum creatinine and estimation of renal function based on its value is very limited. Gold diagnostic standard is radioisotope estimation of glomerular filtration, but this method is not widely available. It seems that this problem may be solved with the use of cystatin C, but this approach needs to be validated in large studies. Numerous different immunosuppressive drugs available on the market enable individualization of immunosuppression. Different drugs combinations may have less nephrotoxic potential, but one must be careful because of the possible risk of organ rejection with the change of immunosuppression. Use of angiotensin convertase enzyme inhibitors and/or angiotensin receptor blockers, statins with drugs for control of hyperglycemia, may prevent or postpone development of CRF. Although technical advances of contemporary hemodialysis machines and peritoneal dialysis equipment enable well tolerated dialysis even in critically ill patients, renal transplantation remains the method of choice for treatment of patients with transplanted parenhimatous organ that developed CRF.

Renal transplantation is method of choice for treatment of patients with end-stage renal disease without contraindications for immunosuppressive therapy. Neurological complications occur frequently in renal transplant recipients. They may be the consequence of immunosuppressive treatment, but more often evolve as the consequence of previous disturbances which developed during the state of uraemia and treatment with dialysis. The most pronounced neurotoxic effect has calcineurin inhibitors tacrolimus and cyclosporine. The spectrum of neurological disturbances caused by calcineurin inhibitors range from very mild symptoms as paraesthesiae, tremor, headache or flushing, to severe changes that may cause lethal outcome. Peripheral neuropathies in renal transplant recipients may occur in the form of mononeuropathy or polyneuropathy. Cerebrovascular diseases are consequence of changes on blood vessels caused by uraemia, dialysis and side effects of immunosuppressive drugs. They cause death in 8% of renal transplant recipients. Central nervous system (CNS) infections usually occur during the first posttransplant year. Unclear symptomatology frequently postpones the diagnosis. Diagnostic evaluation should include magnetic resonance imaging for localization of the process, as well as lumbal puncture in cases without contraindications for the procedure, in order to determine the causative agent. Regarding the ominous prognosis of CNS infections in the immunocompromised host, only timely diagnosis may improve survival. The most common causative agents are Cryptococcus neoformans, Listeria monocytogenes and Aspergillus funigatus. Viral infections also occur, and are commonly caused by herpes virideae, varicella-zoster virus and papova virus. CNS infections clinically present as meningitis, progressive dementia or focal neurological defect. The most common primary brain tumors are B-cell lymphomas, but glioblastoma, hemangioblastoma, leiomyosarcoma or glioma may also occur. In cases of neurological posttransplant complications, optimal treatment should be guided by neurologist, nephrologist and infectologist, in some cases also by neurosurgeons.

Hydrothorax is a rare or late complication of peritoneal dialysis (PD). As often patients are asymptomatic or with mild shortness of breath, hydrothorax is overlooked in many cases. The patient is 72-years old female who was hospitalized in 2005 with clinical and laboratory signs of end stage renal disease (ESRD). Peritoneal catheter was implanted by laparoscopic technique. First postimplantation washouts didn't provoke any symptoms. Shortness of breath appeared on the second day of CAPD and worsened next five days accompanied with right-sided chest pain. Chest X-ray showed massive right-sided pleural effusion which was complitely evacuated by thoracentesis. The laboratory findings showed simmilar glucose levels in dialysate and pleural fluid and normal glucose in serum. The treatment with CAPD was discontinued and later haemodialysis (HD) was commenced.

By the end of 2007 we had 160 patients on CAPD treatment in our centre (44% male, 56% female) aged between 29-78 years. Till 1994 13% of our patients were diabetics. In the last 10 years (1997-2007) the percentage of diabetics increased to 36%. During the 27 years period 44% of our patients died, 35% switched to haemodialysis and 3% have undergone renal transplantation. The survival rate after three years of treatment was 75%, after five years 63% and after 10 years 44%. Technique survival was 77%, 65% and 48% respectively. There were 309 episodes of peritonitis as the main complication of treatment (one episode on every 9, 4 months of treatment till 1994 and one episode on every 25, 8 months in the last ten years), out of which 58% was caused by Gram positive bacteria, 18% by Gram negative, 4% were fungal infections while the remaining 20% were culture negative. Regarding other complications we had 42 exit-site infections and 8 episodes of sclerosing peritonitis with 4 deaths. We found peritonitis to be the main reason of switching to haemodialysis (71%) and the main reason of death (39%) among the patients on CAPD. In the last 10 years (1997-2007) we analyzed the diabetics group separately and we found that the rate of CAPD dropout was not significantly different between diabetics and non-diabetics group. However, when analysing the causes of CAPD dropout, we found significant difference in mortality ate (50% among diabetics versus 26% among non-diabetics) and the rate of switching to haemodialysis (37% versus 55% respectively). In addition we established that the rate of CAPD survival was better after 1994 and we speculate that the main reason is the diminished peritonitis rate.

Therapeutic apheresis is a term that describes numerous different procedures that remove pathological substances from the body. They are used in cases when conservative treatment measures fail, and may be useful as an adjuvant method for treatment of different diseases which have a common feature pathogenic protein substance (paraproteins, antibodies...) or pathogenic substance attached to proteins (toxins), that has to be removed from the body. These substances could be removed by nonselective (plasmapheresis and therapeutic plasma exchange), semiselective (cascade apheresis) or selective methods (different adsorption techniques). The best results are achieved by selective methods, while they remove only pathogenic substances (useful substances remain in plasma), do not require replacement fluid, and have significantly less complications. Different methods of therapeutic apheresis achieved good results in treatment of age-related macular degeneration, sudden hearing-loss, dilatative cardiomyopathy, cardiovascular and cerebrovascular diseases, hepatic failure, inflammatory bowel diseases, and different neurologic conditions like Guillain-Barre syndrome, multiple sclerosis and myastenia gravis. They are useful in renal transplantation for cases with positive crossmatch or AB0 blood group incompatibility, as well as for treatment of acute humoral rejection. Methods of therapeutic apheresis are save and efficient when performed by experienced personel, trained to prevent, timely recognize and treate possible complications.

Cytomegalovirus (CMV) belongs to the family of human herpes viruses. It is also known as the human herpes virus 5 (HHV-5). In immunocompromised host it becomes significant pathogen, causing the spectrum of different symptoms and affecting different tissues and organs. Epidemiologic forms of CMV infection include primary infection, reactivation or secondary infection, and superinfection or reinfection. CMV infection has direct and indirect effects. Direct effects occur at the time of highest viraemia with severe clinical presentation. To the contrast, indirect effects occur at the time of asymptomatic viraemia as the consequence of immunologic response. Indirect effects are mediated by cytokines, chemokines and growth factors. Diagnosis of CMV infection is based on virus detection in body fluids and tissues. There are several diagnostic methods for detection of CMV, and their use is primarily determined by the possibilities of the specific transplantation center. Regarding the risk of CMV infection, several categories of renal transplant recipients may be identified. The main factor for estimation of risk for development of CMV infection is donor and recipient serological status. The highest risk is associated with combination of CMV seropositive donor and CMV seronegative recipient (D+/R-). CMV infection was often fatal before introduction of potent antiviral drugs in therapeutic protocols. Contemporary treatment has significantly decreased mortality rate from the CMV infection. Several drugs are used for prevention and treatment of CMV infection: hyper immune gamma globulin, gancyclovir, valgancyclovir, valacyclovir and acyclovir, depending on the kind of treatment (prophylaxis or preemptive treatment). In the case of CMV disease, the best results may currently be achieved with the combination of hyper immune gamma globulin and intravenous gancyclovir.

Purpose: our experience with color Doppler of arms blood vessels before creation arteriovenous fistula for hemodialysis.

Patients and methods: three years ago all patients who need surgery creation of arteriovenous fistula had Doppler ultrasound preoperative vascular mapping. Purpose of the view is to take a picture of proximal and distal part of arteria radials both arms, distal part of venous cephalica and proximal part of venous mediana antebrachii. We must know if these blood vessels have good morphological and hemodinamic criteria for creation arteiovenous fistula.

Results: in the study were twenty patients, creation of AV fistula was unsuccessful by two patients, but ultrasonic doctor had warning on very gracile blood vessels; by 18 patients in period of 2 to 36 months (mean 12.2 moths) we have optimal effective flow through dialysis filter 300 ml/min, and they are still in good function.

Summary: carefully blood vessels review with color Doppler before creation arteriovenous fistula for hemodialysis, and marking suitable blood vessels with marker on the skin under sonography control reduced unsuccessful number of surgery exploration and destruction of blood vessels if AV fistula don't work. This is very important for hemodialysis patients, especially for diabetics.